You are sitting in the hot tub, when you jump into the pool. You are hit with a rush of cold water. But is it really cold? Your body is warm after being in the hot tub, so when you jump in the pool, your body feels cold, because your body is transfering thermal energy from your body to the pool, in order to make the energy levels the same.
You're cooking soup for dinner. The soup at the bottom of the pan heats up first, and it rises to the top. The cold soup sinks. Why is that? As the soup heats up, the molucles expand, making it less dense, allowing it to rise. The cold soup, being denser, sinks to the bottom. This process repeats until the soup is warm all the way through.
You're sitting beside a campfire, and the fire warms you, but how? We learned that conduction heats through solids, and convection through liquids and gases, but what does radiation use? Radiation actually doesn't use molusles, it uses waves. It uses electro magnetism. Everything radiates heat, its just how much. Radiation does not need to touch things to pass on it's heat.